As a result in particular of the arrival of digital television, the number of television (TV) channels on offer to the user of a TV receiver has increased considerably.
TV mosaics allow the user of a TV receiver to view more rapidly all of the TV programs currently being broadcast on the different channels, without having to consult as many screens as there are channels available.
We consider in this case the mosaics having mosaic elements is juxtaposed such that each mosaic element makes it possible to view, in a reduced format, a content stream, for example a TV program, being broadcast on a channel associated with the mosaic element. Thus, when a mosaic is displayed by the display device, the user views on the same screen a set of the programs broadcast by the channels associated with the mosaic elements of the mosaic.
The video signal viewed via a mosaic element of a mosaic is generally obtained by subsampling of the video signal corresponding to the program.
Generally, the TV channel package provider determines beforehand the N channels which will appear in reduced form in a given mosaic (for example, N is equal to 20 and the mosaic comprises four horizontal rows of mosaic elements, each row comprising five mosaic elements).
The video signal corresponding to each program being broadcast on each of the N channels is firstly subsampled. A mosaic program stream is then constituted as a function of the subsampled video signals. This program stream corresponds to the mosaic screen of the N juxtaposed mosaic elements, each displaying in reduced format the program being broadcast by a respective channel. This mosaic program stream is then broadcast by the provider of packages intended for television receivers, in parallel with broadcasting the streams comprising the original video signals which correspond to the programs being broadcast on the channels.
When a TV channel package provider broadcasts a number of channels greater than the number of mosaic elements which can be juxtaposed on a mosaic screen (in fact the size of a mosaic element must not be too small for it to be viewable when the mosaic is displayed on a TV screen), said provider then broadcasts several mosaics.
When a user subscribes to several package providers, he also receives several mosaics corresponding to the respective providers.
The user therefore has to display several mosaics successively in order to consult the programs broadcast on his favourite channels, which is tedious.
Moreover, the composition of each mosaic is determined by the TV is channel package operator and does not always correspond to the needs of users.
The document WO 2006/081577 describes an electronic program guide composed of dynamic video stream mosaics capable of integrating metadata from different customizable sources. In particular, it proposes a so-called “favourites” mosaic which dynamically integrates video streams corresponding to the user's preferences. Moreover, the user can introduce video stream sources other than that of the video service provider, which will be taken into account during generation of the electronic program guide. The mosaic is generated by the system so as to satisfy the user's preference criteria. The customization system thus proposed can prove to be complex depending on the number and subtlety of the preference criteria and the number of video streams available.